67 Camaro w/LS3 vs vintage air heater valve...
#1
67 Camaro w/LS3 vs vintage air heater valve...
Need a definitive answer to a question that the internet has conflicting info on: The car I’m helping to build is a 67 Camaro with a LS3 based stoker. The HVAC system is a vintage air direct fit unit that uses a single Servo Motor controlled shut off valve for the hot coolant input to the heater core. I’ve read in numerous places that the LS engines require constant flow across the heater circuit in the water pump for proper warmup and operation and I’ve also seen people just put caps on the pump inlet/outlet nipples.... If I use the vintage air shutoff valve, I am stopping flow through the heater circuit as the valve has no provision for bypass flow back into the pump.
Given that the valve is a Servo controlled setup that tells me that Vintage is using it to “throttle” the coolant flow to control heater temp (vs just a blend door position) so using some generic bypass valve isn’t going to work as the heat would be all or nothing...
So what’s the bottom line here? Can LS engines have the heater circuit blocked out in real world driving conditions and operate properly?
Thanks in advance!
S.F.
Given that the valve is a Servo controlled setup that tells me that Vintage is using it to “throttle” the coolant flow to control heater temp (vs just a blend door position) so using some generic bypass valve isn’t going to work as the heat would be all or nothing...
So what’s the bottom line here? Can LS engines have the heater circuit blocked out in real world driving conditions and operate properly?
Thanks in advance!
S.F.
#3
This topic came up on Pro-Touring.com or Lateral G I can't remember. There are a ton of guys running VA with the solenoid and I haven't heard of any problems. I haven't reached the point to first start-up on my LS3 swap but I have the VA and solenoid as well. Check out also Team Camaro.net
#4
TECH Junkie
iTrader: (11)
Seems like mountainous/hilly driving needs the constant flow while us low-load flat-landers can get by with a blocked heater circuit. A couple years ago, Stu-Cool had problems over-heating going up long hills where the engine was seeing constant load. IIRC, the thought was the extra loading was causing issues that us flat-landers never see.
#5
TECH Junkie
iTrader: (1)
I'm using a similar Classic Auto Air (started by ex-V.A. employees I think) set up with an LS3. I simply plumbed a "T" into those heater hoses -- provides a small 1/8" crossover between them. This allows a small amount of flow across the pump at all times as it was designed for. The "T" is small enough that it doesn't interfere with heater operation. It's plumbed into the heater hoses about 6"-8" inches after they leave the t'stat/pump housing. You can see the 4 clamps just to the left of the motor on the passenger side up against the strut tower in the engine shot below.
Attachment 712560
Attachment 712560
Last edited by Michael Yount; 12-31-2017 at 07:24 AM.
#6
Michael Yount,
Clever idea. Thanks for sharing.
Clever idea. Thanks for sharing.
#7
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#8
TECH Junkie
iTrader: (1)
Thx Jimbo - I scratched my head for a while until I realized that if the "T" was small enough on the bypass, it wouldn't affect the heater operation. Car warms up just like OEM, and heater control is perfect. Footnote thanks to Brian Baskin at Delta Current Control who thought the approach would work too.
#9
Thanks to all that replied! I presented the issue to the car’s owner and he wants to integrate a bypass similar to what Mr. Yount came up with. I found the following and he is getting it ordered for me:
https://www.lojkits.com/products/ls-...r-bypass-block
S.F.
https://www.lojkits.com/products/ls-...r-bypass-block
S.F.
#11
S.F.
#14
On The Tree
For anyone else..this will most likely be plug and play if the control systems in the aftermarket AC kit uses servo motors vs steppers. Or you can mount whatever motor on it you need.
http://www.oldairproducts.com/catalo...ve-p-3667.html
http://www.oldairproducts.com/catalo...ve-p-3667.html
#15
TECH Junkie
iTrader: (1)
I talked to folks at Classic Auto Air about a second htr control valve programmed to work opposite of the main valve. Figured I could plumb into a crossover - when heater valve was closed, the crossover valve would open, and vice versa. But they seemed either unable to comprehend or disinterested.
#16
On The Tree
I talked to folks at Classic Auto Air about a second htr control valve programmed to work opposite of the main valve. Figured I could plumb into a crossover - when heater valve was closed, the crossover valve would open, and vice versa. But they seemed either unable to comprehend or disinterested.